Preheat the oven to 325ºF. Line two baking sheets with parchment paper.
In a large bowl, stir together the flaked coconut, sweetened condensed milk, vanilla extract and salt until well combined.
In a separate bowl, whisk the egg whites until stiff peaks form.
Add the whipped egg whites to the coconut mixture and fold until combined.
Using an ice cream scoop or two spoons, scoop out 3-tablespoon mounds of the coconut mixture and arrange them on the baking sheets, spacing each mound 1 inch apart.
Bake the macaroons until dark golden on top, 25 to 30 minutes.
Remove the macaroons from the oven and allow them to cool on the baking sheet for 5 minutes before transferring them to a rack to cool completely.
Melt the chocolate chips and vegetable oil in the microwave or a double-boiler, stirring until smooth. Drizzle the cooled macaroons with the chocolate, top with sprinkles and let set until the chocolate is firm, about 10 minutes.